In an audio-video application of an Internet Protocol (Internet Protocol, IP for short) network, in order to smooth the impact brought by network transmission and implement synchronous play at a receiving end and a sending end, the receiving end needs to temporarily store received audio-video data into a buffer, so as to ensure that the audio-video data still can be played continuously after being transmitted through the IP network. The design of the buffer needs to comprehensively consider the delay and packet loss brought by the buffer. The undersize of the buffer may cause excessive packet losses, and the oversize of the buffer may cause excessive delay of the play. As can be seen from this, a buffer state of the receiving end may directly affect the audio-video play quality. Therefore, it becomes particularly important to assess the audio-video play quality by estimating the state of the buffer.
The prior art is primarily to perform modeling on a buffer in a Real-Time Transport Protocol (Real-Time Transport Protocol, RTP for short)/User Datagram Protocol (User Datagram Protocol, UDP for short) scenario, so as to perform operations such as assessment of the audio-video play quality by estimating the state of the buffer. At present, there are more audio-video applications based on the Transmission Control Protocol (Transmission Control Protocol, TCP for short). Therefore, a buffer state estimation solution for a TCP application scenario is required to provide a condition for assessment of the audio-video play quality in the TCP application scenario.